Superhydrophobic dual-sized filler epoxy composite coatings

Superhydrophobic Surface by Replication of Laser Micromachined Pattern in Epoxy/Alumina Nanoparticle Composite

“…Low viscosity diglycidyl ether of bisphenol-A epoxy resin (Epidian 5, Z. Ch. Organika-Sarzyna, Poland, the average molecular mass of 390, the epoxide equivalent weight of 192-204, the viscosity of 30000 mPa⋅s at 25 ∘ C) was mixed with aluminum oxide nanoparticles (ALNP, Nanostructured & Amorphous Materials Inc., -Al 2 O 3 , 99%, the mean diameter of 11 ± 3 nm, as determined by atomic force microscopy [30]). Amine hardener (IDA, Z. Ch.…”

“…Organika-Sarzyna) at Epidian 5/IDA weight proportion of 1 : 1 w/w was then added and the mixture was ultrasonicated to be assisted with mixing. ALNP concentration of 12 wt.%, in relation to total epoxy and hardener weight, was chosen based on our previous study [30], where such a concentration proved optimal for surface nanotexture development. Degassed nanocomposite was deposited onto PDMS negative masters (Figure 1(g)) and allowed to cure at room temperature for 7 days.…”

“…Hard micro-and nanoparticles are also used to generate hierarchical roughness in polymer composite coatings [28,29]. We have previously reported the applicability of epoxy resin/alumina nanoparticle composites to provide the nanotexture component for the superhydrophobic structure, with elevated erosion resistance [30].…”

Microbumpers maintain superhydrophobicity of nanostructured surfaces upon touch

“…These include nanostructures coating grooves [27,28], micro-pyramids [29] or hillocks [30,31], and micro-pillars [18,[32][33][34][35][36][37][38][39][40]. (We do not include here coatings displaying multiple length scales [41][42][43][44] formed by single-step techniques such as electrodeposition or coating with composites containing multi-sized particles.) Such surfaces have been formed in various ways, including injection [32] or replica [27,33,34,38,40] molding, followed in some cases by nanostructure deposition; micromolding of nanoparticle-containing materials [27,45]; microfabrication (etching) [18,29,35]; microfabrication [37,39,46], sandblasting [30,44] or material deposition [36] followed by surface treatment or other material deposition; and laser microstructuring [28].…”

“…It has been measured using shear and/or load testing [18,40]; abrasion with sand [24,28,29,44,47,48], slurry [33], or a weighted abrasive surface [29,30,43]; or water jet impact [40,49]. In a few recent studies, rubbing with bare fingers has been tested [50][51][52].…”